A considerable number of antitumor agents are administered intravenously, and as such, must be soluble and sufficiently stable. Formulation problems particularly of a solubility nature are investigated. Potential vehicle systems are evaluated for enhancement of solubility of certain poorly water soluble antitumor agents. The inclusion of a non-ionic surfactant in a multicomponent vehicle system has resulted in the resolution of several formulation problems. This approach should be feasible for other compounds that are ethanol soluble but poorly water soluble. The systems developed are currently being evaluated for pharmacologic and toxicologic effects in animals. Analytical methodology for drugs incorporated in the vehicle is also under development. New vehicle combinations will be pursued. The potential antitumor agents having previous formulation problems will be evaluated in these systems.